Below is an excerpt from the Sixteenth American Jurisprudence, Second Edition, Section 256, which affirms that the U.S. Constitution, unless and until LAWFULLY amended as contained within it's express provisions, is a contract between the federal and state government and it's people, and the defacto Law of the Land.
As a contract itself and in spite of U.S. history almost from the moment it was ratified by the 13 original colonies, any and all interpretations or applications of the provisions contained within it under the "common law" upon which contract law is based according to the Magna Carta (used by the founders in their deliberations) by any and all judicial authorities at both the state and federal level is to be done using the "common useage" English definitions in such interpretations or applications pursuant to "contract law doctrine."
The footnote citations relate to U.S. case law which enforces this restatement and can be researched after pulling up the Am.Jur citing for a listing of footnoted case laws at any local law library:
Section 256. Generally. The general rule is that an unconstitutional statute, whether federal  or state,  though having the form and name of law, is in reality no law,  but is wholly void,  and ineffective for any purpose;  since unconstitutionality dates from the time of its enactment, and not merely from the date of the decision so branding it,  an unconstitutional law, in legal contemplation, is as inoperative as if it had never been passed.  Such a statute leaves the question that it purports to settle just as it would be had the statute not been enacted.  No repeal of such an enactment is necessary. 
Since an unconstitutional law is void, the general principles follow that it imposes no duties,  confers no rights,  creates no office,  bestows no power or authority on anyone,  affords no protection,  and justifies no acts performed under it.  A contract which rests on an unconstitutional statute creates no obligation to be impaired by subsequent legislation. 
No one is bound to obey an unconstitutional law  and no courts are bound to enforce it.  Persons convicted and fined under a statute subsequently held unconstitutional may recover the fines paid. 
A void act cannot be legally inconsistent with a valid one.  And an unconstitutional law cannot operate to supersede any existing valid law.  Indeed, insofar as a statute runs counter to the fundamental law of the land, it is superseded thereby.  Since an unconstitutional statute cannot repeal or in any way affect an existing one,  if a repealing statute is unconstitutional, the statute which it attempts to repeal remains in full force and effect.  And where a clause repealing a prior law is inserted in an act, which act is unconstitutional and void, the provision for the repeal of the prior law will usually fall with it and will not be permitted to operate as repealing such prior law. 
The general principles stated above apply to the constitutions as well as to the laws of the several states insofar as they are repugnant to the Constitution and laws of the United States.  Moreover, a construction of a statute which brings it in conflict with a constitution will nullify it as effectually as if it had, in express terms, been enacted in conflict therewith. 
An unconstitutional portion of a statute may be examined for the purpose of ascertaining the scope and effect of the valid portions. 
The numbers in [brackets] are footnotes that refer to court decisions. You can look them up in the American Jurisprudence at any law library.
Juries in the United States have the right and power to judge the law as well as the facts. This means that a jury can acquit a defendant for any reason or none and need not give any reason for it's decision. Therefor bad statutes that are unconstitutional or immoral can be set aside, or good laws that are misapplied can be ignored. This is called "jury nullification."